In screens of displays such as televisions and computer monitors, there is a problem in that displayed images are illegible because light emitted from external light sources such as the sun and fluorescent tubes is reflected on the screen surfaces. In order to solve this problem, the following techniques have been proposed as disclosed in Japanese Unexamined Patent Application Publication Nos. 12-329905 and 13-264508: a technique for irregularly reflecting external light on an irregular surface and a technique for preventing light reflection using a structure including thin-films with low refractive index and thin-films with high refractive index, those thin-films being alternately stacked.
However, the technique for irregularly reflecting external light has another problem in that an image on a display appears blurred. Japanese Unexamined Patent Application Publication Nos. 4-355401, 11-92750, and 11-174971 disclose techniques for providing fluorine compounds having low refractive index on surface layers. Since the fluorine compounds have low surface hardness and therefore have no scratch resistance, those techniques have a problem in that the surface layers are damaged during the assembling of displays or during the cleaning of surfaces and images therefore appear blurred.
It could therefore be advantageous to provide a multilayer film that has high scratch resistance enhanced by increasing the surface hardness of a low-refractive index layer, low reflectance, and high transparency and is useful in preventing reflection. It could also be advantageous to provide a method for manufacturing the film.
Our multilayer film principally has the configuration below. The multilayer film includes a substrate film (a), a hard coat layer (b) containing a (meth)acrylate compound, an electrically conductive layer (c) containing electrically conductive particles, and a resin layer (d) containing a fluorine compound, those layers being disposed on at least one face of the substrate film (a). The resin layer (d) has fine irregularities on the surface and an arithmetic average surface roughness Ra ranging from 0.003 to 0.025 μm and the surface of the resin layer (d) of the multilayer film has a reflectance of less than 2%.
A display film principally has the configuration below. The display film includes the multilayer film, a sticky or adhesive layer placed on a face of the multilayer film that is opposite to the resin layer (d), and a protective film joined to the sticky or adhesive layer.
A display filter principally has the configuration below. The display filter includes the multilayer film joined to the front face of a display with the sticky or adhesive layer placed therebetween.
A front protector panel for plasma display panels principally has the configuration below. The plasma display panel front protector panel includes the multilayer film joined to the front face of a front panel for plasma display panels with the sticky or adhesive layer placed therebetween.
Reference numeral 1 represents the multilayer film, reference numeral 2 represents a substrate film, reference numeral 3 represents a hard coat layer, reference numeral 4 represents an electrically conductive layer, reference numeral 5 represents a resin layer, reference numeral 6 represents an electrically conductive particles, reference numeral 7 represents a fine silica particles, reference numeral 8 represents a front protector panel for plasma display panels, reference numeral 9 represents a glass sheet with an electromagnetic wave-shielding function, and reference numeral 10 represents a sticky layer.